Multiple quantum exceptional, diabolical, and hybrid points in multimode bosonic systems: II. Nonconventional PT-symmetric dynamics and unidirectional coupling

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61989592%3A15310%2F25%3A73633903" target="_blank" >RIV/61989592:15310/25:73633903 - isvavai.cz</a>

Výsledek na webu

<a href="https://quantum-journal.org/papers/q-2025-12-10-1933/pdf/" target="_blank" >https://quantum-journal.org/papers/q-2025-12-10-1933/pdf/</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.22331/q-2025-12-10-1933" target="_blank" >10.22331/q-2025-12-10-1933</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Multiple quantum exceptional, diabolical, and hybrid points in multimode bosonic systems: II. Nonconventional PT-symmetric dynamics and unidirectional coupling

Popis výsledku v původním jazyce

We analyze the existence and degeneracies of quantum exceptional, diabolical, and hybrid points in simple bosonic systems-comprising up to six modes with damping and/or amplification-under two complementary scenarios to those of Ref. [1]: (i) nonconventional PT-symmetric dynamics confined to a subspace of the full Liouville space, and (ii) systems featuring unidirectional coupling. The system dynamics described by quadratic non-Hermitian Hamiltonians is governed by the Heisenberg-Langevin equations. Conditions for the observation of inherited quantum hybrid points with up to sixth-order exceptional and second-order diabolical degeneracies are revealed, though relevant only for short-time dynamics. This raises the question of whether higher-order inherited singularities exist in bosonic systems under general conditions. Nevertheless, for short times, unidirectional coupling of various types enables the concatenation of simple bosonic systems with second-and third-order exceptional degeneracies such that arbitrarily high exceptional degeneracies are reached. Methods for numerical identifying the quantum exceptional and hybrid points together with their degeneracies are addressed. Following Ref. [1] rich dynamics of second-order field-operator moments is analyzed from the point of view of the presence of exceptional and diabolical points and their degeneracies.

Název v anglickém jazyce

Multiple quantum exceptional, diabolical, and hybrid points in multimode bosonic systems: II. Nonconventional PT-symmetric dynamics and unidirectional coupling

Popis výsledku anglicky

We analyze the existence and degeneracies of quantum exceptional, diabolical, and hybrid points in simple bosonic systems-comprising up to six modes with damping and/or amplification-under two complementary scenarios to those of Ref. [1]: (i) nonconventional PT-symmetric dynamics confined to a subspace of the full Liouville space, and (ii) systems featuring unidirectional coupling. The system dynamics described by quadratic non-Hermitian Hamiltonians is governed by the Heisenberg-Langevin equations. Conditions for the observation of inherited quantum hybrid points with up to sixth-order exceptional and second-order diabolical degeneracies are revealed, though relevant only for short-time dynamics. This raises the question of whether higher-order inherited singularities exist in bosonic systems under general conditions. Nevertheless, for short times, unidirectional coupling of various types enables the concatenation of simple bosonic systems with second-and third-order exceptional degeneracies such that arbitrarily high exceptional degeneracies are reached. Methods for numerical identifying the quantum exceptional and hybrid points together with their degeneracies are addressed. Following Ref. [1] rich dynamics of second-order field-operator moments is analyzed from the point of view of the presence of exceptional and diabolical points and their degeneracies.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10306 - Optics (including laser optics and quantum optics)

Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2025

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Quantum

ISSN

2521-327X

e-ISSN

2521-327X

Svazek periodika

9

Číslo periodika v rámci svazku

NOV

Stát vydavatele periodika

AT - Rakouská republika

Počet stran výsledku

32

Strana od-do

"1933-1"-"1933-32"

Kód UT WoS článku

001637089100001

EID výsledku v databázi Scopus

2-s2.0-105024527424